Editorial

As one of the founders of German psychiatry, Griesinger (Wilhelm Griesinger, 1817-1868),
mentioned in his text, ‘Pathologie und Therapie der psychischen Krankheiten (1845)’ that ‘mental
illness is a disease of the brain’ (Geisteskrankheiten sind Gehirnkrankheiten), promoting the place
of psychiatry among modern medicine, and denied the occult interpretation of mental illness after
the medieval period represented by witch-hunting. Based on this thesis, he promoted the scientific
concept of seeking the origin of mental disease in the brain similarly to other physical diseases.
This is the whistling arrow that led to the current biological psychiatry. Griesinger also proposed
Einheitspsychose (Unitary psychosis), stating that the basis of various mental diseases causing
psychosomatic symptoms is a single mental illness.
Adopting this concept of Griesinger, Kraepelin (Emil Kraepelin, 1856-1926), who laid the
foundation for German psychiatry, aimed at elucidating the biological causes of mental disorders.
From these research activities, leading authorities of neuropathology appeared in a large number,
such as Alzheimer (Alois Alzheimer, 1864-1915), who discovered the disease unit of Alzheimer’s
disease, and his pupil, Lewey (Frederic Henry Lewey, 1885-1950). At that time, psychiatry and
neurology were not divided as they are now, and they developed as neuropsychiatry.
At the dawn of psychiatry in Japan, we looked for a model in German psychiatry. In the Japanese
modernization era, many Japanese psychiatrists studied in Germany and absorbed and imported
German psychiatry. One of the persons who acted as a driving force was Shūzō Kure (1865-1932). He
promoted brain pathology research in the psychiatric field with the modernization and reformation
of psychiatric treatment in Japan. He imported brain histological techniques, such as Nissl staining,
from Germany, and performed systematic brain sectioning in the psychiatric field at a psychiatric
hospital. Around that time (1913), Hideyo Noguchi (1876-1928) confirmed the frequent presence of
a pathogenic spirochete in the brain of patients with progressive paralysis hospitalized in psychiatric
hospitals, and identified the cause of the disease.
However, the cause of disease and pathology of mood disorders including schizophrenia and
depression are still mysteries in the psychiatric field. These diseases had been actively studied from
the era of Kraepelin using neuropathological techniques, but this methodology had limitations and
neuropathology started to decline in the psychiatric field, with it being said that ‘schizophrenia is a
graveyard for neuropathologists’. In the 1980s, morphological changes and the abnormal running
of nerve fibers in the brain of patients with schizophrenia were suggested by neuroimaging studies
conducted one after another. In addition, it was said that when genes composing the brain (i.e.,
blueprint of brain tissue) are clarified with the progression of molecular psychiatry, the causes of
mental diseases will be elucidated. Actually, several candidate genes were discovered in schizophrenia
patients, and the involvement of many functions of these genes in neural network formation has
been clarified. In addition, model animals were prepared based on a risk gene, the DISC1 gene,
identified in a multiplex schizophrenia family, and several neuropathological abnormalities have
been discovered by neuropathologically investigating this model. However, for studies using these
model animals, verification in the postmortem human brain is essential. Moreover, the cause of
disease and pathology cannot be elucidated by neuroimaging or molecular-psychiatric studies
alone, and these studies require convergence by confirming the histopathology of the postmortem
human brain.
However, brain tissue as a study resource had not been accumulated in Japan because
neuropathological studies for psychiatry declined. Moreover, the autopsy rate is generally low in
Japan compared with those in Western countries, perpetuating the difficulty in acquiring resources,
being a major obstacle to the promotion of studies in Japan, and many Japanese researchers inevitably
depended on brain banks of Western countries. The Japanese Society of Biological Psychiatry has
investigated the necessity of a ‘Japanese version of the psychiatric brain bank’ to promote research in Japan for about the last 10 years, and ethical, methodological, and
technical problems have been discussed referring to the preceding
brain banks of Western countries. Through these academic activities,
a project to accumulate brain tissues was initiated by the Japan
Agency for Medical Research and Development (AMED) in 2015
using national research funds. At present, several institutions in Japan
have collaborated and started a ‘Japanese version of the psychiatric
brain bank’ through accumulating postmortem brains of patients
with mental diseases and neuropathy.
In neuropathy, there is a historical background of brain resource
accumulation in the neurology field including that of dementia, but
it is very difficult to replace diseased brain tissue once they have been
depleted. Even so, the thesis of Griesinger, ‘mental illness is a disease
of the brain’, has guided the history of psychiatry, and it is clear that
this project has to succeed to overcome mental diseases. Therefore,
I will promote psychiatric clinicians’ awareness of the medical
necessity of the brain bank and inform patients of the importance
of donating brains for medical research, and construct a Japanese
version of psychiatric brain bank comparable to those of Western
countries, expecting it to play a major role in overcoming all mental
diseases through cooperation with brain banks of Western countries
and effective utilization on a global scale.